The Statement Beginning Balance changes once the Bank Reconciliation and Credit Card Reconcile is final saved.
Both the Statement Ending and Beginning balance would be changed if a transaction was cleared directly in the 1-3 journal transactions.
The Statement Beginning and Ending balance in the Bank Reconciliation can also be affected if a transaction was previously reconciled, then changed directly in the 1-3 journal transactions at a later time. This is also true if a transaction previously reconciled gets voided.